I'm using this on Heroku and occasionally seeing this error: An EventMachine loop must be running to use publish_async calls.

Have you seen anything like this? I assume that for some reason the EventMachine crashed but the dyno remained alive. Do you have any suggestions for how to handle that case? Could I restart the EventMachine from inside one of my unicorn forks?

To @elihuu - hard to say what that might be. It could be a stray event loop, but stop should be getting called. If something is going wrong in the event loop, you might be able to find it by registering a global error handler.